1. Field of the Invention
The present invention relates to circuits for selectively gating data signals, and in particular, to signal gating controllers for selectively gating out undesired pulses from improperly equalized data signals.
2. Description of the Related Art
Recovering data from data signals which have been transmitted over long lengths of cable at high data rates requires that such data signals be equalized in order to compensate for the signal loss and phase dispersion characteristics of the cable. Further, in those applications where the cable length may vary, such equalization must be capable of adapting according to the length of the cable. Conventional adaptive equalization is typically accomplished through the use of a feedback control signal having an amplitude which is proportional to the pulse height of the equalized data signal. However, such a technique for controlling the adaptive equalization process is very sensitive to amplitude errors in the incoming data signal and can often result in under-equalized or over-equalized signals. In such improperly equalized signals, false signal peaks can occur which result in false, and therefore undesired, decoded data pulses. Accordingly, it would be desirable to have a signal gating controller capable of gating out such false decoded data pulses and thereby compensate for improperly equalized signals.